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A study of tau decays of the W boson at CDF (Collider Detector at Fermilab) (open access)

A study of tau decays of the W boson at CDF (Collider Detector at Fermilab)

A report is given of a search for tau decays of the W boson in p{bar p} collisions at {radical}s = 1.8 TeV using the Collider Detector at Fermilab (CDF). A description of a hardware trigger specifically designed to enhance the number of events with tau decays is presented along with the results of a preliminary analysis of data taken during the 1988--89 run of CDF. 10 refs., 4 figs.
Date: January 3, 1990
Creator: Gladney, L. D.
System: The UNT Digital Library
New generation of arc and arc filament power supplies for pulsed neutral beams (open access)

New generation of arc and arc filament power supplies for pulsed neutral beams

The new Tandem Mirror Experiment (TMX) facility at LLL requires that neutral beams operate for pulse lengths between 25 and 100 ms. The inevitable increase in cost over the present 12-ms pulse length capability dictated that a more economical alternative to the pulse forming networks and the transformer-type arc filament power supplies currently in use be found. A study of the various alternatives and design requirements revealed that battery banks are the most economical alternative. The thermionic arc filaments have relatively simple power-supply requirements in terms of control and regulation. The battery arc filament power supply controls and electromechanical hardware heat the filaments to provide the electrons which produce the plasma. Component testing revealed problems that must be addressed in the finished production design. The battery arc power supply poses a difficult set of requirements for current control. The TMX requires current control accuracy of +-1.0 percent and rise/fall times of 50 ..mu..s. These requirements are met with a novel thyristor switching circuit. The features of the four-section battery bank design, capable of a total of 4000 A at 58 V dc, are detailed. Control hardware compatible with the current generation of pulse-forming network hardware has been developed. The cost …
Date: October 3, 1977
Creator: Santamaria, G.T.
System: The UNT Digital Library
Evaluating late detection capability against diverse insider adversaries (open access)

Evaluating late detection capability against diverse insider adversaries

This paper describes a model for evaluating the late (after-the-fact) detection capability of material control and accountability (MCandA) systems against insider theft or diversion of special nuclear material. Potential insider cover-up strategies to defeat activities providing detection (e.g., inventories) are addressed by the model in a tractable manner. For each potential adversary and detection activity, two probabilities are assessed and used to fit the model. The model then computes the probability of detection for activities occurring periodically over time. The model provides insight into MCandA effectiveness and helps identify areas for safeguards improvement. 4 refs., 4 tabs.
Date: December 3, 1987
Creator: Sicherman, A.
System: The UNT Digital Library
Prospects for top at CDF (open access)

Prospects for top at CDF

During the next two years, the Fermilab Tavatron is expected to deliver approximately 100pb{sup {minus}1} of integrated luminosity. We describe improvements to the CDF detector since the 1988--89 collider run and discuss the prospects for the discovery of the top quark during the 1992--93 collider runs.
Date: June 3, 1992
Creator: Gerdes, D. (Chicago Univ., IL (United States))
System: The UNT Digital Library
50th Anniversary, 1931-1981: symposium and banquet speeches (open access)

50th Anniversary, 1931-1981: symposium and banquet speeches

The proceedings includes talks given at the symposium and the banquet. They include examples of technology at the laboratory and speculation on the future at the laboratory. (GHT)
Date: October 3, 1981
Creator: unknown
System: The UNT Digital Library
Numerical methods for laser fusion (open access)

Numerical methods for laser fusion

The LASNEX computer code was developed to study the many interrelated physical processes important in the effort to achieve laser initiated fusion. It has been used to calculate the results of numerous laser plasma experiments and to design targets and determine desirable laser pulse characteristics for future experiments. Some processes, such as hydrodynamics, are well formulated in fundamental equations and can be solved with high accuracy by sophisticated numerical methods. Other processes, such as laser absorption and electron transport, are less well understood and do not, in general, warrant the use of highly accurate techniques. Numerical models were chosen that adequately represent each physical process, keeping in mind its inherent uncertainties, the importance of the process to the overall calculation, and its effect on the determination of experimental observables.
Date: November 3, 1977
Creator: Zimmerman, G.B.
System: The UNT Digital Library
Two-component flow study in large-diameter horizontal pipe (open access)

Two-component flow study in large-diameter horizontal pipe

Westinghouse Savannah River Company, Idaho National Engineering Laboratory, and Wyle Laboratory cooperated in a series of single- and two-component calibration tests conducted to obtain sufficient information for calibrating flowmeters, to observe flow patterns, and to estimate void functions. Testing, conducted in large-diameter horizontal pipe, covered total flows of 0.19 to 1.89 m{sup 3}/s (3000 to 30000 gpm) and inlet void fractions up to 40%. A flow regime map, constructed using video images of the flow patterns and void fraction data, was compared with maps from the literature, with generally good agreement for interpretation of flow patterns. 5 refs.
Date: December 3, 1991
Creator: Eghbali, D. A.
System: The UNT Digital Library
Implicit Plasma Simulation (open access)

Implicit Plasma Simulation

Implicit time integration methods have been used extensively in numerical modelling of slowly varying phenomena in systems that also support rapid variation. Examples include diffusion, hydrodynamics and reaction kinetics. This article discussed implementation of implicit time integration in plasma codes of the ''particle-in-cell'' family, and the benefits to be gained.
Date: March 3, 1985
Creator: Langdon, A. B.
System: The UNT Digital Library
Simultaneously time- and space-resolved spectroscopic characterization of laser-produced plasmas (open access)

Simultaneously time- and space-resolved spectroscopic characterization of laser-produced plasmas

The CHROMA laser facility at KMS Fusion has been used to irradiate a variety of microdot targets. These include aluminum dots and mixed bromine dots doped with K-shell (magnesium) emitters. Simultaneously time- and space-resolved K-shell and L-shell spectra have been measured and compared to dynamic model predictions. The electron density profiles are measured using holographic interferometry. Temperatures, densities, and ionization distributions are determined using K-shell and L-shell spectral techniques. Time and spatial gradients are resolved simultaneously using three diagnostics: a framing crystal x-ray spectrometer, an x-ray streaked crystal spectrometer with a spatial imaging slit, and a 4-frame holographic interferometer. Significant differences have been found between the interferometric and the model-dependent spectral measurements of plasma density. Predictions by new non-stationary L-shell models currently being developed are also presented. 14 refs., 10 figs.
Date: March 3, 1988
Creator: Charatis, G.; Young, B. K. F.; Busch, G. E.; Cerjan, C. J.; Goldstein, W. H.; Osterheld, A. L. et al.
System: The UNT Digital Library
Engineering of beam direct conversion for a 120-kV, 1-MW ion beam (open access)

Engineering of beam direct conversion for a 120-kV, 1-MW ion beam

Practical systems for beam direct conversion are required to recover the energy from ion beams at high efficiency and at very high beam power densities in the environment of a high-power, neutral-injection system. Such an experiment is now in progress using a 120-kV beam with a maximum total current of 20 A. After neutralization, the H/sup +/ component to be recovered will have a power of approximately 1 MW. A system testing these concepts has been designed and tested at 15 kV, 2 kW in preparation for the full-power tests. The engineering problems involved in the full-power tests affect electron suppression, gas pumping, voltage holding, diagnostics, and measurement conditions. Planning for future experiments at higher power includes the use of cryopumping and electron suppression by a magnetic field rather than by an electrostatic field. Beam direct conversion for large fusion experiments and reactors will save millions of dollars in the cost of power supplies and electricity and will dispose of the charged beam under conditions that may not be possible by other techniques.
Date: October 3, 1977
Creator: Barr, W. L.; Doggett, J. N.; Hamilton, G. W.; Kinney, J. D. & Moir, R. W.
System: The UNT Digital Library
Propagation of a heavy ion beam in gas-filled reactor (open access)

Propagation of a heavy ion beam in gas-filled reactor

A heavy ion beam traversing a gas-filled reactor is stripped of its electrons along its path. The propagation of the stripping beam with possible associated instabilities has been investigated.
Date: November 3, 1977
Creator: Yu, S. S.; Buchanan, H. L.; Chambers, F. W. & Lee, E. P.
System: The UNT Digital Library
CAMAC serial highway interface for the LSI-11 (open access)

CAMAC serial highway interface for the LSI-11

A CAMAC Serial Highway Interface has been designed for the Local Control and Instrumentation System of the Mirror Fusion Test Facility. There are over 50 distinguishable systems in the facility, each of which consists of the LSI-11 computer, fiber optic communication links, and the CAMAC system. The LSI-11 computer includes a 32k memory, serial modem interface and the CAMAC Serial Highway Interface.
Date: April 3, 1980
Creator: Lau, N.H.
System: The UNT Digital Library
Neutron scattering analysis with microscopic optical model potentials (open access)

Neutron scattering analysis with microscopic optical model potentials

A review of microscopic optical model potentials used in the analysis of neutron scattering and analyzing power data below 100 MeV (5 {le}E{sub n}{le}100 MeV) is presented. The quality of the fits to the data over a wide massd ({sup 6}Li-{sup 239}Pu) and energy range is discussed. It is shown that reasonably good agreement with the data is obtained with only three parameters, {lambda}{sub V}, {lambda}{sub W}, and {lambda}{sub SO}, which show a smooth mass and energy dependence. These parameters are normalizing constants to the real (V), and imaginary (W) central potentials and the real spin-orbit (V{sub SO}) potential. 14 refs., 7 figs.
Date: September 3, 1991
Creator: Hansen, L. F.
System: The UNT Digital Library
Recent developments in the Virasoro master equation (open access)

Recent developments in the Virasoro master equation

The Virasoro master equation collects all possible Virasoro constructions which are quadratic in the currents of affine Lie g. The solution space of this system is immense, with generically irrational central charge, and solutions which have so far been observed are generically unitary. Other developments reviewed include the exact C-function, the superconformal master equation and partial classification of solutions by graph theory and generalized graph theories. 37 refs., 1 fig., 1 tab.
Date: September 3, 1991
Creator: Halpern, M.B.
System: The UNT Digital Library
Atomic data needs for beam transport in gas (open access)

Atomic data needs for beam transport in gas

Determination of the parameters Z/sub eff/, electrical conductivity, plasma density, and the plasma temperature is essential in the study of heavy ion beam transport in gas. The calculation of these parameters require input from atomic physics. This note is an attempt to make these needs known to atomic physicists.
Date: November 3, 1977
Creator: Yu, S. S.
System: The UNT Digital Library
Microchannel plate as a detector of minimum ionizing particle (open access)

Microchannel plate as a detector of minimum ionizing particle

Micro-channel plate multipliers have been used to detect the passage of relativistic charged particles. Measurements of the detection efficiency and pulse height response versus micro-channel plate gain are presented for one, two and three micro-channel plate arrays. The probability of detecting an avalanche on the detector anode per one channel of MCP crossed by the relativistic particle was calculated. Temporal response and time jitter were measured and are reported. The track images of beam particles crossing the detector are shown.
Date: September 3, 1980
Creator: Oba, K; Rehak, P & Smith, S D
System: The UNT Digital Library
CDF: Recent results and future prospects (open access)

CDF: Recent results and future prospects

We present recent results from the Collider Detector at Fermilab. Searches for the top quark have established a lower bound of M{sub top} > 91 GeV/c{sup 2} (at 95% confidence level). A measurement of B{sup o}{bar B}{sup o} mixing has been obtained from b{bar b} {yields} e{mu}, ee events. Measurements of b-quark production have been obtained from e + X events and J/{psi} + K events. The mass of the W boson has been determined to be M{sub W} = 79.91 {plus minus} 0.39 GeV/c{sup 2}. In searching for new gauge bosons, we have obtained the bounds M{sub Z{prime}} > 412 GeV/c{sup 2} and M{sub W{prime}} > 520 GeV/c{sup 2} (at 95% C.L.). The lower limits on the quark and lepton compositeness scales are 1.4 TeV. In the next two years of data collection, we expect significantly more events for numerous types of physics, due to 25 times more beam luminosity, and improvement to the detector. In the longer term, the Main Injector'' upgrade to the accelerator, further improvements to the detector are being planned to exploit the potentials for physics. We discuss prospects for the discovery of the top quark, precise measurement of properties of b quark, and searches …
Date: March 3, 1992
Creator: Yeh, G.P.
System: The UNT Digital Library
Acceleration systems for heavy-ion beams for inertial confinement fusion (open access)

Acceleration systems for heavy-ion beams for inertial confinement fusion

The requirements for a heavy-ion demonstration experiment to achieve useful electric power generation through inertial confinement fusion are discussed. (MOW)
Date: October 3, 1977
Creator: Faltens, A.; Judd, D.L. & Keefe, D.
System: The UNT Digital Library
Serial interprocessor communications system (open access)

Serial interprocessor communications system

A serial communications system based on the EIA RS232-C standard with modem control lines has been developed. The DLV11-E interface is used for this purpose. All handshaking is done with the modem control lines. This allows totally independent full duplex communication. The message format consists of eight bit data with odd parity and a sixteen bit checksum on the whole message. All communications are fully interrupt driven. A program was written to load a program into a remote LSI-11 using the serial line without bootstrap ROM.
Date: April 3, 1980
Creator: Labiak, W.; Siemens, P. & Bailey, C.
System: The UNT Digital Library
Environmental and Genetic Preconditioning for Long-Term Anoxia Responses Requires AMPK in Caenorhabditis elegans (open access)

Environmental and Genetic Preconditioning for Long-Term Anoxia Responses Requires AMPK in Caenorhabditis elegans

Article on environmental and genetic preconditioning for long-term anoxia responses requires AMPK in Caenorhabditis elegans.
Date: February 3, 2011
Creator: LaRue, Bobby L. & Padilla, Pamela A.
System: The UNT Digital Library
Equivalence of dipole correction and Coulomb cutoff techniques in supercell calculations (open access)

Equivalence of dipole correction and Coulomb cutoff techniques in supercell calculations

Article on the equivalence of dipole correction and Coulomb cutoff techniques in supercell calculations. In this work, the authors compare the dipole correction and Coulomb cutoff methods under the same conditions in the framework of plane-wave based density-functional theory.
Date: June 3, 2008
Creator: Yu, Liping; Ranjan, Vivek; Lu, W.; Bernholc, Jerry & Buongiorno Nardelli, Marco
System: The UNT Digital Library
Cassette blanket and vacuum building: key elements in fusion reactor maintenance (open access)

Cassette blanket and vacuum building: key elements in fusion reactor maintenance

The integration of two concepts important to fusion power reactors is discussed. The first concept is the vacuum building which improves upon the current fusion reactor designs. The second concept, the use of the cassette blanket within the vacuum building environment, introduces four major improvements in blanket design: cassette blanket module, zoning concept, rectangular blanket concept, and internal tritium recovery. (MHR)
Date: October 3, 1977
Creator: Werner, R.W.
System: The UNT Digital Library
Spectrochemical analysis of plutonium using direct current plasma emission spectrometry (open access)

Spectrochemical analysis of plutonium using direct current plasma emission spectrometry

One year ago, LLNL was just completing the installation of a Direct Current Plasma (DCP) spectrometer for the analysis of Pu and Pu alloys. The installation was completed in December 1982 and has been utilized regularly for Pu analysis since then. This paper discusses the experience with the instrument and some data demonstrating its performance.
Date: December 3, 1983
Creator: Morris, W.F.; Fadeff, S.K. & Torres, S.
System: The UNT Digital Library
Progress and prospects for soft x-ray lasing driven by high power optical lasers (open access)

Progress and prospects for soft x-ray lasing driven by high power optical lasers

We will describe our optical laser pumped xuv Laser Program. To date, we have concentrated our efforts on exploding foil amplifier designs using Ne-like n=3p to 3s inversion schemes. We will describe our latest modeling results as well as measurements which demonstrate output power near the 1 MW level at 206 and 209 A and lasing at wavelengths as short as 106 A.
Date: July 3, 1986
Creator: Rosen, M.D.; Matthews, D.L. & Hagelstein, P.L.
System: The UNT Digital Library